Trivalent phosphorus compounds stabilized with amines

ABSTRACT

The invention relates to a process for stabilizing a crystalline organic phosphite or phosphonite against hydrolysis, which comprises introducing a mixture comprising phosphite or phosphonite, a solvent or solvent mixture, and 0.1 to 100% by weight (relative to phosphite or phosphonite) of an amine and having a temperature of 50°-100° C. as a homogeneous melt into a liquid crystallization medium whose temperature during the addition is maintained 10°-70° C. below the temperature of the melt. 
     The phosphites or phosphonites stabilized according to the invention are distinguished by their excellent resistance to hydrolysis and have a long shelf life even at high atmospheric humidity. They can be advantageously used as stabilizers for organic material against the damaging effect of heat, oxygen, and/or light.

This is a divisional of Ser. No. 08/129,705, filed Sep. 30, 1993, now U.S. Pat. No. 5,371,263.

The invention relates to a process for increasing the shelf life of organic phosphites and phosphonites and to an organic phosphite or phosphonite stabilized against hydrolysis.

Organic phosphites and phosphonites are widely used as heat stabilizers for synthetic polymers. However, preparation, storage and use of phosphites and phosphonites are rendered difficult by the fact that these compounds hydrolyze very easily. A particular problem is storage of the material at high atmospheric humidity.

Various methods have been proposed for arriving at products having improved stability to hydrolysis; these include, apart from preparation processes leading to purer products and methods for purifying the ready-to-use compounds, in particular the addition of specific stabilizers which, on the one hand, reduce the tendency to hydrolysis and, on the other hand, do not result in adverse effects during the later use of the compounds.

EP-A-278 579 proposes to use a hydrolytically stable stabilizer mixture in which the crystalline phosphite is embedded in an amorphous phenolic antioxidant. This stabilizer mixture is obtainable by rapid cooling of a melt of both compounds or of a suspension consisting of crystalline phosphite and liquid phenol derivatives.

The addition of amines as stabilizers against hydrolysis is described, for example, in U.S. Pat. No. 3 553 298. Further publications regarding the stabilization of phosphites with amines are U.S. Pat. No. 3 787 537, EP-A-168 721 and EP-A-167 969. The recommended compounds are in particular tertiary alkanolamines and alkylamines, pyridines and anilines; typical examples are triethylamine, diethanolamine, triethanolamine, di- and triisopropanolamine (TIPA), tetraisopropanolethylenediamine, aniline, phenylenediamine and hexamethylenetetramine. In general, the amines are used in amounts of up to about 5% by weight (relative to the phosphite to be stabilized); incorporation of the amine is effected by dry milling or by dissolution in or mixing with the phosphite melt, followed by crystallization.

Despite the known stabilization methods listed here, there is a need for further improvement of the hydrolyric stability of organic phosphites and phosphonites.

It has now been found that the stabilizing effect of amines can surprisingly be increased by applying the amine in a special process.

Accordingly, the invention provides a process for stabilizing a crystalline organic phosphite or phosphonite against hydrolysis, which comprises introducing a mixture comprising phosphite or phosphonite, a solvent or solvent mixture, and 0.1 to 100% by weight (relative to the phosphite or phosphonite ) of an amine and having a temperature of 50°-100° C. as a homogeneous melt into a liquid crystallization medium whose temperature during the addition is maintained 10°-70° C. below the temperature of the melt.

The melt is the liquid mixture comprising amine, solvent and the phosphite or phosphonite to be stabilized. The melt can contain a small or a large amount of solvent, for example 20 or 500% by weight (relative to the phosphite or phosphonite) and thus can also be more like a solution. The important feature is that the melt is homogeneous, i.e. that none of the components mentioned are crystalline any more and separation into 2 or more liquid phases does not take place. The amine used can be an individual compound or a mixture of compounds.

In principle, any organic compounds or mixtures of compounds which are liquid in the temperature range from 10° to 60° C. under atmospheric pressure, do not cause solvolysis and are capable of dissolving a sufficient amount of solid phosphite or phosphonite above 50° C., in some cases up to 100° C. or are sufficiently miscible with the melted phosphite or phosphonite, can be used as the solvent. For example, sufficient solubility or miscibility is given if the homogeneous liquid mixture can contain up to 15, in particular up to 50% , by weight of phosphite or phosphonite. Examples of suitable solvents are alcohols or hydrocarbons or mixtures thereof.

Advantageously one compound or a mixture of two compounds is used as the solvent in the melt. The main solvent is used in an amount of 20 to 500% by weight, relative to the phosphite or phosphonite, and the further solvent in an amount of 0-50% by weight, relative to the main solvent. The melt preferably contains an alcohol or a hydrocarbon as the main solvent in an amount of 20 to 500% by weight, relative to the phosphite or phosphonite, and a further solvent in an amount of 0-50, in particular 0-20, % by weight, relative to the main solvent. It is also possible to use a mixture of alcohols or a mixture of hydrocarbons.

Examples of suitable alcohols are lower alcohols, such as C₁ -C₅ alkanols, in particular C₁ -C₃ alkanols, such as methanol, ethanol, propanol or isopropanol. Isopropanol and methanol are particularly suitable.

Examples of suitable hydrocarbons are C₆ -C₁₃ alkanes, cycloalkanes or alkylated cycloalkanes having 6 to 12 carbon atoms, benzene, or alkylaromatics having 6 to 10 atoms; toluene, ligroin, petroleum ether, xylene, and in particular toluene are particularly suitable.

Frequently the further solvent used is a hydrocarbon or a mixture of hydrocarbons in the case where the main solvent is an alcohol, or an alcohol in the case where the main solvent is a hydrocarbon. Suitable alcohols and hydrocarbons are the ones listed above.

The organic phosphites or phosphonites usable according to the invention are solid at 20° C.; in general they are crystalline solids.

Phosphites are here understood to mean organic phosphites of the formula P(OR)₃ in which the radicals R are hydrocarbon radicals, which may contain hetero atoms, and moreover a maximum of two of the three radicals R can be hydrogen atoms. Hetero atoms are any atoms with the exception of carbon and hydrogen, in particular the atoms N, O, F, Si, P, S, Cl, Br, Sn and I.

Phosphonites are esters of phosphonous acid of the formula P(OR)₂ R in which R is as defined above or can be halogen.

In the process according to the invention, crude phosphite or crude phosphonite solutions such as are obtained during preparation before crystallization can be used.

The product of the process according to the invention is a mixture of compounds comprising solid phosphite or phosphonite and amine.

The temperature of the melt is preferably 55°-90° C., in particular 60°-80° C.

In the process according to the invention, the difference in temperature between melt and crystallization medium is advantageously at least 20° C., for example 30°-70° C., in particular 40-60° C.

The crystallization medium is preferably maintained at a temperature being at least 10° C., for example 10°-60° C., below the resulting temperature of the liquidus. The temperature of the crystallization medium is preferably 20°-60° C. below the resulting temperature of the liquidus.

The resulting temperature of the liquidus is the temperature at which a homogeneous phase formed from the melt and crystallization medium is in thermodynamic equilibrium with phosphite crystals; below this temperature, crystallization starts, and above the mixture forms a homogeneous melt. In practice, this temperature is advantageously determined by mixing tests, for example by means of calorimetic (for example by DSC) and/or optical methods.

Advantageously, 80-800% by weight, in particular 100-500% by weight, of organic solvent, relative to the phosphite or phosphonite in the melt, is used as the crystallization medium.

Advantageously, alcohols are used as the crystallization medium; thus, for example, a C₁ -C₅ alkanol or a mixture of various C₁ -C₅ alkanols is used. C₁ -C₃ Alkanols, such as methanol, ethanol, propanol or isopropanol, are preferably used as the crystallization medium.

Advantageously, seed crystals are added to the crystallization medium. Accordingly, the crystallization medium preferably consists of a suspension of 2 to 20% by weight of crystalline phosphite or phosphonite, relative to the phosphite or phosphonite in the melt. Moreover, it is advantageous for the crystallization medium to be 50-100% saturated with the amine, 100% of saturation corresponding to an amine concentration at which dissolved and solid amine can be present side by side.

In general, the melt contains 0.1 to 50% by weight of amine, relative to the phosphite or phosphonite; preferably, 0.2 to 25% by weight, in particular 0.5 to 20% by weight, in particular 1 to 10% by weight, are used (relative to the phosphite or phosphonite in the melt).

During the metered addition of the melt, the crystallization medium is advantageously stirred. After both mixtures have been combined, further workup can take place in a manner known per se, for example by cooling to 10°-15° C. and isolation of the crystalline product.

The stabilized phosphite or phosphonite is generally obtained as a powder in which the amine is homogeneously distributed. Typically it contains 0.01 to 20, in particular 0.05 to 10, in particular 0.1 to 5, % by weight of amine (relative to the phosphite or phosphonite).

The amine used in the process according to the invention is preferably a sterically hindered amine or one of the formula I ##STR1## in which X¹ and X², independently of one another, are H, C₁ -C₂ alkyl, C₄ -C₂₀ which is interrupted by one or more --O--and unsubstituted or substituted by one or more hydroxyl groups, or is C₂ -C₂₀ hydroxyalkyl, and X³ is C₂ -C₂₀ alkyl, C₄ -C₂₀ alkyl which is interrupted by one or more --O--and unsubstituted or substituted by one or more hydroxyl groups, or is --(CH₂)_(m) --NX¹ X², or C₂ -C₂₀ hydroxyalkyl, or in which X² and X³ together are --(CH₂)_(m) --, --C₂ H₄ --O--C₂ H₄ -- or --C₂ H₄ --NX¹ C₂ H₄ --, m being an integer from the range 4 to 6 and X¹ and X² being as defined above.

The sterically hindered amine is in general a cyclic sterically hindered amine, in particular a compound from the series of polyalkylpiperidine or -piperazine derivatives containing a group of the formulae II or III ##STR2## in which G is hydrogen or methyl, and G₁ and G₂ are hydrogen, methyl or together are ═O; preferably, the polyalkylpipefidine group of the formula II or III are substituted in the 4 position by one or two polar substituents or a polar spiro ring system.

X¹, X² and X³ are, for example, independently of one another, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, hydxoxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, hydroxyhexyl, hydroxyheptyl, hydroxyoctyl, hydroxynonyl or hydroxydecyl.

Preferably, X¹, X² and X³ are identical.

The amine of the formula I is preferably a tertiary amine, particularly preferably a tri--C₂ -C₄ alkanolamine, in particular triisopropanolamine (═amine A).

Of importance is a process in which the amine used is a tertiary amine of the formula I or a cyclic sterically hindered amine containing at least one group of the formulae II or III in which G is hydrogen, and G¹ and G² are hydrogen or together are a substituent ═O.

Particularly advantageously, derivatives of 2,2,6,6-tetramethylpipefidine are used in the process according to the invention.

Of importance is in particular the use of the classes of polyalkylpipefidines described below under (a) to (h), which carry a group of the formula II or III as mentioned above:

(a) compounds of the formula IV ##STR3## in which n is a number from 1 to 4, G and G¹, independently of one another, are hydrogen or methyl,

G¹¹ is hydrogen, oxyl, hydroxyl, C₁ -C₁₈ alkyl, C₃ -C₈ alkenyl, C₃ -C₈ alkynyl, C₇ -C₁₂ aralkyl, C₁ -C₁₈ alkoxy, C₄ -C₈ cycloalkoxy, C₆ -C₉ phenylalkoxy, C₁ -C₈ alkanoyl, C₃ -C₅ alkenoyl, C₁ -C₁₈ alkanoyloxy, benzyloxy, glycidyl or a group --CH₂ CH(OH)--Z, in which Z is hydrogen, methyl or phenyl, G¹¹ being preferably H, C₁ -C₄ alkyl, allyl, benzyl, acetyl or acryloyl and

G¹² being, in the case where n is 1, hydrogen, C₁ -C₁₈ alkyl which may be interrupted by one or more oxygen atoms, cyanoethyl, benzyl, glycidyl, a monovalent radical of an aliphatic, cycloaliphatic, araliphatic, unsaturated or aromatic carboxylic acid, carbamic acid or phosphorus-containing acid or a monovalent silyl radical, preferably a radical of an aliphatic carboxylic acid having 2 to 18 C atoms, a cycloaliphatic carboxylic acid having 7 to 15 C atoms, an α, β-unsaturated carboxylic acid having 3 to 5 C atoms or an aromatic carboxylic acid having 7 to 15 C atoms it being possible for the carboxylic acid to be substituted in each case in the aliphatic, cycloaliphatic or aromatic portion by 1 to 3 groups --COOZ¹², in which Z¹² is H, C₁ -C₂₀ alkyl, C₃ -C₁₂ alkenyl, C₅ -C₇ cycloalkyl, phenyl or benzyl,

in the case where n is 2, C₂ -C₁₂ alkylene, C₄ -C₁₂ alkenylene, xylylene, a divalent radical of an aliphatic, cycloaliphatic, araliphatic or aromatic dicarboxylic acid, dicarbamic acid or phosphorus-containing acid, or a divalent silyl radical, preferably a radical of an aliphatic dicarboxylic acid having 2 to 36 C atoms, a cycloaliphatic or aromatic dicarboxylic acid having 8-14 C atoms, or an aliphatic, cycloaliphatic or aromatic dicarbamic acid having 8-14 C atoms, it being possible for the dicarboxylic acid to be substituted in each case in the aliphatic, cycloaliphatic or aromatic portion by 1 or 2 groups --COOZ¹²,

in the case where n is 3, a trivalent radical of an aliphatic, cycloaliphatic or aromatic tricarboxylic acid, which may be substituted in the aliphatic, cycloaliphatic or aromatic portion by --COOZ¹², an aromatic tricarbamic acid or a phosphorus-containing acid, or a trivalent silyl radical, and

in the case where n is 4, a tetravalent radical of an aliphatic, cycloaliphatic or aromatic tetracarboxylic acid.

The carboxylic acid radicals mentioned include in each case radicals of the formula (--CO)_(n) R, the meaning of n being given above and the meaning of R being apparent from the definition given.

Examples of C₁ -C₁₂ alkyl substituents, if present, are methyl, ethyl, n-propyl, n-butyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl or n-dodecyl.

Examples of G¹¹ or G¹² as C₁ -C₁₈ alkyl can be the abovementioned groups and in addition, for example, n-tridecyl, n-tetradecyl, n-hexadecyl or n-octadecyl.

Examples of G¹¹ as C₃ -C₈ alkenyl can be 1-propenyol, allyl, methallyl, 2-butenyl, 2-pentenyl, 2-hexenyl, 2-octenyl, 4-ten-butyl-2-butenyl.

G¹¹ as C₃ -C₈ alkynyl is preferably propargyl.

G¹¹ as C₇ -C₁₂ aralkyl is in particular phenethyl and especially benzyl.

Examples of G¹¹ as C₁ -C₈ alkanoyl are formyl, propionyl, butyryl, octanoyl, but preferably acetyl and as C₃ -C₅ alkenoyl in particular acryloyl.

G¹² as a monovalent radical of a carboxylic acid is, for example, an acetic acid, caproic acid, stearic acid, acrylic acid, methacrylic acid, benzoic acid or β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid radical.

G¹² as a monovalent silyl radical is, for example, a radical of the formula --(C_(j) H_(2j))--Si(Z')₂ Z", in which j is an integer from the range 2 to 5, and Z' and Z", independently of one another, are C₁ -C₄ alkyl or C₁ -C₄ alkoxy.

G¹² as a divalent radical of a dicarboxylic acid is, for example, a malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, maleic acid, iraconic acid, phthalic acid, dibutylmalonic acid, dibenzylmalonic acid, butyl(3,5-di-tert-butyl-4-hydroxybenzyl)malonic acid or bicycloheptenedicarboxylic acid radical.

G¹² as a trivalent radical of a tricarboxylic acid is, for example, a trimellific acid, citric acid or nitrilotriacetic acid radical.

G¹² as a tetravalent radical of a tetracarboxylic acid is, for example, the tetravalent radical of butane-1,2,3,4-tetracarboxylic acid or of pyromellitic acid.

G¹² as a divalent radical of a dicarbamic acid is, for example, a hexamethylenedicarbamic acid or a 2,4-toluylenedicarbamic acid radical.

Preference is given to compounds of the formula IV in which G is hydrogen, G¹¹ is hydrogen or methyl, n is 2, and G¹² is the diacyl radical of an aliphatic dicarboxylic acid having 4-12 C atoms.

Examples of polyalkylpiperidine compounds from this class are the following compounds:

1) 4-hydroxy-2,2,6,6-tetramethylpiperidine

2) 1-allyl-4-hydroxy-2,2,6,6-tetramethylpiperidine

3) 1-benzyl-4-hydroxy-2,2,6,6-tetramethylpiperidine

4) 1-(4-tert-butyl-2-butenyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine

5) 4-stearoyloxy-2,2,6,6-tetramethylpiperidine

6) 1-ethyl-4-salicyloyloxy-2,2,6,6-tetramethylpiperidine

7) 4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidine

8) 1,2,2,6,6-pentamethylpiperidin-4-yl β-(3,5-di-ten-butyl-4-hydroxyphenyl)propionate

9) di(1-benzyl-2,2,6,6-tetramethylpiperidin-4-yl)maleate

10) di(2,2,6,6-tetramethylpiperidin-4-yl) succinate

11) di(2,2,6,6-tetramethylpiperidin-4-yl) glutarate

12) di(2,2,6,6-tetramethylpiperidin-4-yl) adipate

13) di(2,2,6,6-tetramethylpiperidin-4-yl) sebacate

14) di(1,2,2,6,6-pentamethylpiperidin-4-yl) sebacate

15) di(1,2,3,6-tetramethyl-2,6-diethyl-piperidin-4-yl) sebacate

16) di(1-allyl-2,2,6,6-tetramethylpiperidin-4-yl) phthalate

17) 1-hydroxy-4-β-cyanoethyloxy-2,2,6,6-tetramethylpiperidine

18) 1-acetyl-2,2,6,6-tetramethylpiperidin-4-yl acetate

19) trimellitic acid tri-(2,2,6,6-tetramethylpiperidin-4-yl)ester

20) 1-acryloyl-4-benzyloxy-2,2,6,6-tetramethylpiperidine

21) di(2,2,6,6-tetramethylpiperidin-4-yl) diethylmalonate

22) di-(1,2,2,6,6-pentamethylpiperidin-4-yl) dibutylmalonate

23) di(1,2,2,6,6-pentamethylpiperidin-4-yl) butyl(3,5-di-tert-butyl-4-hydroxybenzyl)malonate

24) di(1-octyloxy-2,2,6,6-tetramethylpiperidin-4-yl) sebacate

25) di(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl) sebacate

26) hexane-1 ', 6 '-bis(4-carbamoyloxy-1-n-butyl-2,2,6,6-tetramethyl-piperidine)

27) toluene-2', 4 '-bis(4-carbamoyloxy-1-n-propyl-2,2,6,6-tetramethyl-piperidine)

28) dimethylbis(2,2,6,6-tetramethylpiperidine-4-oxy)silane

29) phenyltris(2,2,6,6-tetramethylpiperidin-4-oxy)silane

30) tris(1-propyl-2,2,6,6-tetramethylpiperidin-4-yl) phosphite

31) tris(1-propyl-2,2,6,6-tetramethylpiperidin-4-yl) phosphate

32) bis-( 1,2,2,6,6-pentamethylpiperidin-4-yl) phenylphosphonate

33) 4-hydroxy-1,2,2,6,6-pentamethylpiperidine

34) 4-hydroxy-N-hydroxyethyl-2,2,6,6-tetramethylpiperidine

35) 4-hydroxy-N-(2-hydroxypropyl)-2,2,6,6-tetramethylpiperidine

36) 1 -glycidyl-4-hydroxy-2,2,6,6-tetramethylpiperidine

(b) compounds of the formula (V) ##STR4## in which n is 1 or 2, G, G¹ and G¹¹ have the meaning given under (a), G¹³ is hydrogen, C₁ -C₁₂ alkyl, C₂ -C₅ aydroxyalkyl, C₅ -C₇ cycloalkyl, C₇ -C₈ aralkyl, C₂ -C₁₈ alkanoyl, C₃ -C₅ alkenoyl, benzoyl or a group of the formula ##STR5## and G¹⁴ is, in the case where n is 1, hydrogen, C₁ -C₁₈ alkyl, C₃ -C₈ alkenyl, C₅ -C₇ cycloalkyl,

C₁ -C₄ alkyl which is substituted by a hydroxyl, cyano, alkoxycarbonyl or carbamide group, or is glycidyl, a group of the formula --CH₂ --CH(OH)--Z or of the formula --CONH--Z, in which Z is hydrogen, methyl or phenyl;

in the case where n is 2, C₂ -C₁₂ alkylene, C₆ -C₁₂ arylene, xylylene, a --CH₂ --CH(OH)--CH₂ -- or a group --CH₂ --CH(OH)--CH₂ --O--D--O--, in which D is C₂ -C₁₀ alkylene,

C₆ -C₁₅ arylene, C₆ -C₁₂ cycloalkylene, or, provided G¹³ is not alkanoyl, alkenoyl or benzoyl, G¹⁴ can also be 1--oxo--C₂ -C₁₂ alkylene, a divalent radical of an aliphatic, cycloaliphatic or aromatic dicarboxylic acid or dicarbamic acid or else the group --CO--, or, in the case where n is 1, G¹³ and G¹⁴ together can be the divalent radical of an aliphatic, cycloaliphatic or aromatic 1,2- or 1,3-dicarboxylic acid.

C₁ -C₁₂ Alkyl or C₁ -C₁₈ alkyl substituents, if present, have the meaning already given under (a).

C₅ -C₇ Cycloalkyl substitutents, if present, are in particular cyclohexyl.

G¹³ as C₇ -C₈ aralkyl is in particular phenylethyl or especially benzyl. G¹³ as C₂ -C₅ hydroxyalkyl is in particular 2-hydroxyethyl or 2-hydroxypropyl.

Examples of G¹³ as C₂ -C₁₈ alkanoyl are propionyl, butyryl, octanoyl, dodecanoyl, hexadecanoyl, octadecanoyl, but preferably acetyl and, as C₃ -C₅ alkenoyl, in particular acryloyl.

Examples of G¹⁴ as C₂ -C₈ alkenyl are allyl, methallyl, 2-butenyl, 2-pentenyl, 2-hexenyl or 2-octenyl.

Examples of G¹⁴ as C₁ -C₄ alkyl which is substituted by a hydroxyl, cyano, alkoxycarbonyl or carbamic group can be 2-hydroxyethyl, 2-hydroxypropyl, 2-cyanoethyl, methoxycarbonylmethyl, 2-ethoxycarbonylethyl, 2-aminocarbonylpropyl or 2-(dimethylaminocarbonyl)ethyl.

Examples of C₂ -C₁₂ alkylene substituents, if present, are ethylene, propylene, 2,2-dimethylpropylene, tetramethylene, hexamethylene, octamethylene, decamethylene or dodecamethylen.

Examples of C₆ -C₁₅ arylene substituents, if present are o-, m- or p-phenylene, 1,4-naphthylene or 4,4'-diphenylene.

A C₆ -C₁₂ cycloalkylene is in particular cyclohexylene.

Preference is given to compounds of the formula V in which n is 1 or 2, G is hydrogen,

G¹¹ is hydrogen or methyl, G¹³ is hydrogen, C₁ -C₁₂ alkyl or a group of the formula ##STR6## and G¹⁴ is hydrogen or C₁ -C₁₂ alkyl in the case where n=1 and C₂ -C₈ alkylene or 1--oxo--C₂ -C₈ alkylene in the case where n is 2.

Examples of polyalkylpiperidine compounds of this class are the following compounds:

37) N,N'-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylene-1,6-diamine

38) N,N'-bis(2,2,6,6-tetramethylpipefidin4-yl)hexamethylene-1,6-diacetamide

39) bis(2,2,6,6-tetramethylpiperidin-4-yl)amine

40) 4-benzoylamino-2,2,6,6-tetramethylpiperidine

41) N,N'-bis(2,2,6,6-tetramethylpiperidin4-yl)-N,N'4ibutyladipamide

42) N,N'-bis(2,2,6,6-tetramethylpiperidin-4-yl)-N,N'-dicyclohexyl-2-hydroxypropylene1,3-diamine

43) N,N'-bis(2,2,6,6-tetramethylpiperidin-4-yl)-p-xylylene diamine

44) N,N'-bis(2,2,6,6-tetramethylpipefidin4-yl)succinediamide

45) di(2,2,6,6-tetramethylpipefidin-4-yl) N-(2,2,6,6-tetramethylpipefidin4-yl)-Baminodipropionate aminodipropionate

46) the compound of the formula ##STR7## 47) 4-[bis(2-hydroxyethyl)amino]-1,2,2,6,6-pentamethylpiperidine 48) 4-(3-methyl-4-hydroxy-5-ten-butylbenzamido)-2,2,6,6-tetramethylpiperidine

49) 4-methacrylamido-1,2,2,6,6-pentamethylpiperidine

(c) compounds of the formula (VI) ##STR8## in which n is 1 or 2, G, G¹ and G¹¹ have the meaning given under (a), and G¹⁵ is C₂ -C₈ alkylene or -hydroxyalkylene or C₄ -C₂₂ acyloxyalkylene, in the case where n is 1, and is the group (--CH₂)₂ C(CH₂ --)₂, in the case where n is 2.

Examples of G¹⁵ as C₂ -C₈ alkylene or -hydroxyalkylene are ethylene, 1-methylethylene, propylene, 2oethylpropylene or 2-ethyl-2-hydroxymethylpropylene.

G¹⁵ as C₄ -C₂₂ acyloxyalkylene is, for example, 2-ethyl-2-acetoxymethylpropylene.

Examples of polyalkylpiperidine of this class axe the following compounds:

50) 9-aza-8,8,10,10-tetramethyl-1,5-dioxaspiro[5.5]undecane

51) 9-aza-8,8,10,10-tetramethyl-3-ethyl-1,5-dioxaspiro[5.5]undecane

52) 8-aza-2,7,7,8,9,9-hexamethyl-1,4-dioxaspiro[4.5]decane

53) 9-aza-3-hydroxymethyl-3-ethyl-8,8,9,10,10-pentamethyl-1,5-dioxaspiro[5.5]undecane

54) 9-aza-3-ethyl-3-acetoxymeth yl-9-acetyl-8,8,10,10-tetramethyl-1,5-dioxaspiro[5.5]-undecane

55) 2,2,6,6-tetramethylpiperidine-4-spiro-2 '-(1', 3'-dioxane)-5'-spiro-5"-(1",3"-dioxane)-2"-spiro-4"'-(2"', 2"', 6"', 6"'-tetramethylpiperidine ).

(d) Compounds of the formulae VIIAt, VIIB and VIIC, preference being given to compounds of the formula VIIC ##STR9## in which n is 1 or 2, G, G¹ and G¹¹ have the meaning given under (a), G¹⁶ is hydrogen, C₁ -C₁₁ alkyl, allyl, benzyl, glycidyl or C₂ -C₆ alkoxyalkyl and G¹⁷ is, in the case where n is 1, hydrogen, C₁ -C₁₂ alkyl, C₃ -C₅ alkenyl, C₇ -C₉ aralkyl, C₅ -C₇ cycloalkyl, C₂ -C₄ hydroxyalkyl, C₂ -C6alkoxyalkyl, C₆ -C₁₀ aryl, glycidyl or a group of the formula --(CH₂)p--COO-Q or of the formula --(CH₂)p-O--CO--Q, in which p is 1 or 2 and Q is C₁ -C₄ alkyl or phenyl, and, in the case where n is 2, C₂ -C₁₂ alkylene, C₄ -C₁₂ alkenylene, C₆ -C₁₂ arylene, a group --CH₂ --CH(OH)--CH₂ --O--D--O--CH₂ CH(OH)--CH₂ --, in which D is C₂ -C₁₀ alkylene, C₆ -C₁₅ arylene, C₆ -C₁₂ cycloalkylene, or a group --CH₂ CH(OZ')CH₂ --(OCH₂ --CH(OZ')CH₂)₂ --, in which Z' is hydrogen, C₁ -C₁₈ alkyl, allyl, benzyl, C₂ -C₁₂ alkanoyl or benzoyl, T₁ and T₂, independently of one another, are hydrogen, C₁ -C₁₈ alkyl or unsubstituted or halogen- or C₁ -C₄ alkyl-substituted C₆ -C₁₀ aryl or C₇ -C₉ aralkyl, or T₁ and T₂ together with the C atom linking them form a C₅ -C₁₄ cycloalkane ring.

Examples of C₁ -C₁₂ alkyl substituents, if present, are methyl, ethyl, n-propyl, n-butyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl or n-dodecyl.

Examples of C₁ -C₁₈ alkyl substituents, if present, can be the abovementioned groups and in addition, for example, n-tridecyl, n-tetradecyl, n-hexadecyl or n-octadecyl.

Examples of C₂ -C₆ alkoxyalkyl substituents, if present, are methoxymethyl, ethoxymethyl, propoxymethyl, tert-butoxymethyl, ethoxyethyl, ethoxypropyl, n-butoxyethyl, tert-butoxyethyl, isopropoxyethyl or propoxypropyl.

Examples of G¹⁷ as C₃ -C₅ alkenyl are 1-propenyl, allyl, methallyl, 2-butenyl or 2-pentenyl.

G¹⁷, T₁ and T₂ as C₇ -C₉ aralkyl are in particular phenethyl or especially benzyl. A cycloalkane ring formed by T₁ and T₂ together with the C atom can be, for example, a cyclopentane, cyclohexane, cyclooctane or cyclododecane ring.

Examples of G¹⁷ as C₂ -C₄ hydroxyalkyl are 2-hydroxyethyl, 2-hydroxypropyl, 2-hydroxybutyl or 4-hydroxybutyl.

G¹⁷, T₁ and T₂ as C₆ -C₁₀ aryl are in particular phenyl, α- or β-naphthyl, which are unsubstituted or substituted by halogen or C₁ -C₄ alkyl.

Examples of G¹⁷ as C₂ -C₁₂ alkylene are ethylene, propylene, 2,2-dimethylpropylene, tetramethylene, hexamethylene, octamethylene, decamethylene or dodecamethylene.

G¹⁷ as C₄ -C₁₂ alkenylene is in particular 2-butenylene, 2-pentenylene or 3-hexenylene.

Examples of G¹⁷ as C₆ -C₁₂ arylene are o-, m- or p-phenylene, 1,4-naphthylene or 4,4'-diphenylene.

Examples of Z' as C₂ -C₁₂ alkanoyl are propionyl, butyryl, octanoyl, dodecanoyl, but preferably acetyl.

D as C₂ -C₁₀ alkylene, C₆ -C₁₅ arylene or C₆ -C₁₂ cycloalkylene is as defined under (b).

Examples of polyalkylpiperidine compounds of this class are the following compounds:

56) 3-benzyl-1,3,8-triaza-7,7,9,9-tetramethylspiro[4.5]decane-2,4-dione

57) 3-n-octyl-1,3,8-triaza-7,7,9,9-tetramethylspiro[4.5]decane-2,4-dione

58) 3-allyl-1,3,8-triaza-1,7,7,9,9-pentamethylspiro[4.5]decane-2,4-dione

59) 3-glycidyl-1,3,8-triaza-7,7,8,9,9-pentamethylspiro[4.5]decane-2,4-dione

60) 1,3,7,7,8,9,9-heptamethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione

61) 2-isopropyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxospiro-[4.5]decane

62) 2,2-dibutyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxospiro-[4.5]-decane

63) 2,2,4,4-tetramethyl-7-oxa-3,20-diaza-21 -oxodispiro[5.1.11.2 ]-heneicosane

64) 2-butyl-7,7,9,9-tetramethyl-1 -oxa-4,8-diaza-3-oxospiro[4.5]decane

and preferably:

65) 8-acetyl-3-dodecyl-1,3,8-triaza-7,7,9,9-tetramethylspiro[4.5]-decane-2,4-dione

or the compounds of the following formulae: ##STR10## (e) Compounds of the formula VIII, which on their part are preferred, ##STR11## in which n is 1 or 2 and G¹⁸ is a group of one of the formulae ##STR12## in which G and G¹¹ are as defined under (a) and G¹ and G² are hydrogen, methyl or together are a substiment ═O,

E is --O-- or --NG¹³ --,

A is C₂ -C₆ alkylene or --(CH₂)₃ --O-- and

x is 0 or 1,

G¹³ is hydrogen, C₁ -C₁₂ alkyl, C₂ -C₅ hydroxyalkyl or C₅ -C₇ cycloalkyl,

G¹⁹ is identical to G¹⁸ or one of the groups --NG²¹ G₂₂, --OG²³, --NHCH₂ OG²³ or --N(CH₂ OG²³)₂,

G²⁰ is identical to G¹⁸ or G¹⁹ in the case where n is 1, and is a group --E--B--E--, in which B is C₂ -C₈ alkylene or C₂ -C₈ alkylene which is interrupted by 1 or 2 --N(G²¹)-- groups, in the case where n is 2,

G²¹ is C₁ -C₁₂ alkyl, cyclohexyl, benzyl, C₁ -C₄ hydroxyalkyl or a group of the formula ##STR13## G²² is C₁ -C₁₂ alkyl, cyclohexyl, benzyl, C₁ -C₄ hydroxyalkyl, and

G²³ is hydrogen, C₁ -C₁₂ alkyl or phenyl, or G²¹ and G²² together are C₄ -C₅ alkylene or --oxaalkylene, for example ##STR14## or a group of the formula ##STR15## is a group fo the formula ##STR16##

Any C₁ -C₁₂ alkyl substituents present are, for example, methyl, ethyl, n-propyl, n-butyl, sec-butyl, tert-butyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, n-undecyl or n-dodecyl.

Any C₁ -C₄ hydroxyalkyl substituents present are, for example, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 2-hydroxybutyl or 4-hydroxybutyl.

Examples of A as C₂ -C₆ alkylene are ethylene, propylene, 2,2-dimethylpropylene, tetramethylene or hexamethylene.

Examples of G²¹ and G²² together as C₄ -C₅ alkylene or oxaalkylene are tetramethylene, pentamethylene or 3-oxapentamethylene.

Examples of polyalkylpiperidine compounds of this class are the compounds of the following formulae: ##STR17## (f) oligomers or polymer compounds whose recurring structural unit contains a 2,2,6,6-tetraalkylpiperidine radical of the formula III, in particular polyesters, polyethers, polyamides, polyamines, polyurethanes, polyureas, polyaminotriazines, poly(meth)acrylates, poly(meth)acrylamides and copolymers thereof containing such radicals.

Examples of 2,2,6,6-polyalkylpiperidine light stabilizers of this class are the compounds of the following formulae, m being a number from 2 to about 200. ##STR18## R being ##STR19## or a branching of the chain ##STR20## m' and m" are each an integer from the range 0-200 on condition that m'+m" is m.

Further examples of polymer light stabilizers are reaction products of compounds of the formula ##STR21## with epichlorohydrin; polyesters obtained by reaction of butane-1,2,3,4-tetracarboxylic acid with a bifunctional alcohol of the formula ##STR22## the carboxyl side chains of which originating from the tetracarboxylic acid have been esterified with 2,2,6,6-tetramethyl-4-hydroxypiperidine;

compounds of the formula ##STR23## in which about one third of the radicals R are --C₂ H₅ and the others are, ##STR24## and m is a number from the range 2 to 200; or copolymers whose recurring unit is composed of 2 units ##STR25## and 1 unit of each ##STR26## (g) Compounds of the formula IX ##STR27## in which G, G¹ and G¹¹ are as defined under (a).

Preference is given to compounds of the formula IX in which G is hydrogen or methyl and G¹¹ is hydrogen or methyl.

Examples of such compounds are:

96) 2,2,6,6-tetramethyl-4-piperidone (triacetoneamine)

97) 1,2,2,6,6-pentamethyl-4-piperidone

98) 2,2,6,6-tetramethyl-4-piperidone 1-oxide

99) 2,3,6-trimethyl-2,6-diethyl-4-piperidone

(h) compounds of the formula X ##STR28## in which n is 1 or 2 and in which G and G¹¹ are as defined under (a) and G¹⁴ is as defined under (b), the meanings --CONH--Z and --CH₂ --CH(OH)--CH₂ --O--D--O-- being excluded for G¹⁴.

Examples of such compounds are: ##STR29##

The following amines are particularly preferred for use in the process according to the invention:

Compounds of the formula IV in which n is an integer from the range 1 to 4, G and G¹ are hydrogen, and

G¹¹ is hydrogen or C₁ -C₁₈ alkyl, and

G¹², in the case where n is 1, is a radical of the formula --(C_(j) H_(2j))--Si(Z')₂ Z", in which j is an integer from the range 2 to 5 and Z' and Z", independently of one another, are C₁ -C₄ alkyl or C₁ -C₄ alkoxy, and

G¹², in the case where n is 2, is a radical of an aliphatic dicarboxylic acid having 2 to 12 C atoms which may be substituted by --COOZ¹², Z² being C₁ -C₂₀ alkyl,

G¹², in the case where n is 3, is a radical of an aromatic tricarboxylic acid having 9 to 15 C atoms,

G¹², in the case where n is 4, is a radical of an aliphatic tetracarboxylic acid having 8 to 12 C atoms; amines from this class which are of particular technical interest are those of the formulae ##STR30## and esters of butane-1,2,3,4-tetracarboxylic acid with 2 units each of 1,2,2,6,6-penta-methyl-4-hydroxy-piperidine and C₁₃ H₂₇ --OH (amine F);

compounds of the formula V in which n is 2, G and G¹ are hydrogen,

G¹¹ is hydrogen or methyl and

G¹³ is hydrogen or C₁ -C₈ alkyl, and

G¹⁴ is C₂ -C₈ alkylene or 1--oxo--C₂ -C₈ alkylene; an amine from this class which is of particular technical interest is the compound of the formula ##STR31## compounds of the formula VIIC in which n is 1, G, G¹ and G¹⁷ are hydrogen,

G¹¹ is hydrogen or methyl and

T₁ and T₂ together with the C atom linking them form a C₅ -C₁₄ cycloalkane ring; an amine from this class which is of particular technical interest is the compound of the formula ##STR32## compounds of the formula VIII in which n is 1 or 2 G¹⁸ and G¹⁹ are a group of one of the formulae ##STR33## G¹¹ is hydrogen or methyl, G¹ and G² are hydrogen or together are a substituent ═O,

E is --O-- or --NG¹³ --,

A is C₂ -C₆ alkylene and

x is 0 or 1,

G¹³ is hydrogen, C₁ -C₁₂ alkyl or cyclohexyl,

G²⁰ , in the case where n is 1, is identical to G¹⁸ and, in the case where n is 2, is a group --E--B--E--, in which B is C₂ -C₈ alkylene or C₂ -C₈ alkylene which is interrupted by 1 or 2 groups --N(G²¹)--,

G²¹ is C₁ -C₁₂ alkyl, cyclohexyl, benzyl or C₁ -C₄ hydroxyalkyl or a group of the formula ##STR34## or G²¹ is a group of the formula ##STR35## amines from this class which are of particular technical interest are the compound 76) [═amine J] described above and the compounds of the formulae ##STR36## compounds of the formula X in which n is 2, G¹¹ is hydrogen or methyl and G¹⁴ is C₂ -C₁₂ alkylene;

an amine from this class which is of particular technical interest is the compound 100) [=amine M] described above; and

oligomer compounds having 2 to 10 recurring units, such as are obtainable by reaction of ##STR37## in which G²⁴ is C₂ -C₅ hydroxyalkyl with an aliphatic C₂ -C₁₂ dicarboxylic acid or a suitable reactive derivative, such as the diester, dichloride or anhydride;

(j) of a linear oligomer polyester obtained by reaction of a dialcobol with butane-1,2,3,4-temacarboxylic acid with 2,2,6,6-tetramethyl-4hydroxypiperidine; ##STR38## in which A is C₂ -C₆ alkylene, T³ is C₁ -C₁₈ alkylene or cyclohexyl, T⁴ is hydrogen or C₁ -C₁₈ alkyl, or T³ and T⁴ together are C₄ -C₆ alkylene or C₃ -C₅ oxaalkyylene;

(l) of H₂ N--A--NH--A--NH₂ with ##STR39## and Br--A--Br, in which A is C₂ -C₆ alkylene; (m) of compounds of the formula ##STR40## with epichlorohydrin; (n) of ##STR41## and those of the formula (o) ##STR42## in which about one third of the radicals R are --C₂ H₅ and the other are ##STR43## and m is a number from the range 2 to 10; oligomer amines of particular technical interest include those of the formulae (m again is a number from the range 2 to 10) ##STR44## in which about one third of the radicals R are --C₂ H₅ and the others are ##STR45## a linear polyester having 2 to 10 recurring units obtained by reaction of butane-1,2,3,4-tetracarboxylic acid with a dialcohol of the formula ##STR46## in which the end groups and side chains are formed by esterificadon of the free carboxyl groups with 2,2,6,6-tetramethyl-4-hydroxypiperidine (amine S); a copolymer whose recurring units are composed of 2 units ##STR47## and 1 unit each of ##STR48## the reaction product of H₂ N--(CH₂)₂ --NH--(CH₂)₂ --NH₂ with ##STR49## and Br--(CH₂)₂ --Br (amine U); and the reaction product of the compound of the formula ##STR50## with epichlorohydrin (amine W).

The oligomer amines are often mixtures of compounds which differ from one another with respect to their chain length.

Of particular importance is the use of the amines A, B, C, D, E, F, G, H, J, K, L, M, N, O, P, Q, R, S, T, U, V and W specified above.

In the process according to the invention, preference is given in particular to the addition of those amines whose molecular weight or average molecular weight M_(n) is in the range 300 to 10,000, in particular in the range 1000 to 10,000. Of these, those amines whose molecular weight or average molecular weight M_(n) is in the range 1500 to 10,000, for example in the range 2000 to 7500 should again be mentioned in particular. The amines of higher molecular weight are in particular sterically hindered amines.

The amines mentioned are known compounds; many of them are commercially available.

In the process according to the invention preference is given to stabilization of phosphites or phosphonites having one of the formulae (1) to (7), ##STR51## in which the indices are integers and n' is 2, 3 or 4; p is 1 or 2; q is 2 or 3; r is 4 to 12; y is 1, 2 or 3; and z is 1 to 6;

A', in the case where n' is 2, is alkylene having 2 to 18 carbon atoms; alkylene which is interrupted by --S--, --O-- or --NR'₄ -- and has 2 to 12 carbon atoms; a radical of one of the formulae ##STR52## or phenylene; A', in the case where n' is 3, is a radical of the formula --C_(r) H_(2r-1) --;

A', in the case where n' is 4, is a radical of the formula C(CH₂)₄ ;

A", in the case where n' is 2, has the meaning of A';

B' is a radical of the formula --CH₂ --; --CHR'₄ --; --CR'₁ R'₄ --; --S-- or a direct bond; or is C₅ -C₇ cycloalkylidene; or is cyclohexylidene which is substituted in the 3, 4 and/or 5 position by 1 to 4 C₁ -C₄ alkyl radicals;

D', in the case where p is 1, is methyl and, in the case where p is 2, is --CH₂ OCH₂ --;

E', in the case where y is 1, is alkyl having 1 to 18 carbon atoms, phenyl, a radical of the formula --OR'₁ or halogen;

E', in the case where y is 2, is a radical of the formula --O--A"--O--;

E', in the case where y is 3, is a radical of the formula R'₄ C(CH₂ O )₃ ;

Q' is the radical of an at least z-valent alcohol or phenol, this radical being attached to the

P atom(s) via the alcoholic or phenolic O atom(s);

R'₁, R'₂ and R'₃, independently of one another, are alkyl having 1 to 30 carbon atoms; alkyl which is substituted by halogen,--COOR₄ ', --CN or --CONR₄ 'R₄ ' and has 1 to 18 carbon atoms; alkyl which is interrupted by --S--, --O-- or --NR'₄, and has 2 to 18 carbon atoms; phenyl--C₁ -C₄ alkyl; cycloalkyl having 5 to 12 carbon atoms; phenyl or naphthyl; phenyl or naphthyl each of which is substituted by halogen, 1 to 3 alkyl radicals or alkoxy radicals having a total of 1 to 18 carbon atoms or by phenyl--C₁ -C₄ alkyl; or is a radical of the formula ##STR53## in which m is an integer from the range 3 to 6 R'₄ or the radicals R₄ ' independently of one another, are hydrogen; alkyl having 1 to 18 carbon atoms; cycloalkyl having 5 to 12 carbon atoms; or phenylalkyl having 1 to 4 carbon atoms in the alkyl moiety;

R'₅ and R'₆, independently of one another, are hydrogen; alkyl having 1 to 8 carbon atoms or cycloalkyl having 5 or 6 carbon atoms;

R'₇ and R'₈, in the case where q is 2, are, independently of one another, C₁ -C₄ alkyl or together are a 2,3-dehydropentamethylene radical; and

R'₇ and R'₈, in the case where q is 3, are methyl; the substituents R'₁₄, independently of one another, are hydrogen; alkyl having 1 to 9 carbon atoms or cyclohexyl;

the substituents R'₁₅, independently of one another, are hydrogen or methyl; and

R'16 is hydrogen or C₁ -C₄ alkyl and, in the case where several radicals R'₁₆ are present, the radicals R'₁₆ are identical or different;

X' and Y' are each a direct bond or --O--; and

Z' is a direct bond; --CH₂ --; --C(R'₁₆)₂ -- or --S--.

Particular preference is given to a process in which the phosphite or phosphonite is one of the formulae (1), (2), (5) or (6), in which

n' is 2 and y is 1 or 2;

A' is alkylene having 2 to 18 carbon atoms; p-phenylene or p-biphenylene;

E', in the case where y is 1, is C₁ -C₁₈ alkyl, --OR₁ or fluorine; and, in the case where y is 2, is p-biphenylene;

R'₁, R'₂ and R'₃, independently of one another, are alkyl having 1 to 18 carbon atoms; phenyl--C₃ -C₄ alkyl; cyclohexyl; phenyl; phenyl which is substituted by 1 to 3 alkyl radicals having a total of 1 to 18 carbon atoms;

the substituents R'₁₄, independently of one another, are hydrogen or alkyl having 1 to 9 carbon atoms;

R'₁₅ is hydrogen or methyl;

X' is a direct bond;

Y' is --O--; and

Z' is a direct bond or --CH(R'₁₆)--.

Of particular technical interest is a process for stabilizing a phosphite or phosphonite of one of the formulae (1), (2), (5) or (6), in which

n' is 2 and y is 1;

A' is p-biphenylene;

E' is C₃ -C₁₈ alkoxy;

R'₁, R'₂ and R'₃, independently of one another, are phenyl which is substituted by 2 or 3 alkyl radicals having a total of 2 to 12 carbon atoms;

the substituents R'₁₄, independently of one another, are methyl or tert-butyl;

R'₁₅ is hydrogen;

X' is a direct bond;

Y' is --O--; and

Z' is a direct bond, --CH₂ -- or --CH(CH₃)--.

Particular preference is given to phosphites, in particular those of the formulae (1) and (5).

The following compounds are examples of phosphites and phosphonites whose stability to hydrolysis can be improved particularly advantageously by the process according to the ##STR54##

The phosphites and phosphonites mentioned are known compounds; some of them are commercially available.

Some commercial phosphites and phosphonites are present as mixtures of compounds or in prestabilized form. In most cases, an mine, for example a lower alkylamine or triisopropanolamine, has been admixed to these compounds in a conventional manner in a concentration of about 1% as prestabilization. The hydrolytic stability of such products can also be significantly improved by the process according to the invention. The products of the process according to the invention can advantageously be used as stabilizers for organic material, in particular organic polymers, for example synthetic polymers, against the damaging effect of heat, oxygen and/or light. Examples of such polymers can be seen, for example, from U.S. Pat. No. 4 855 345, column 4, line 63, up to column 7, line 54.

The phosphites and phosphonites stabilized according to the invention are distinguished by their excellent resistance to hydrolysis and have a long shelf life even at high atmospheric humidity. An organic phosphite or phosphonite stabilized against hydrolysis, such as obtainable by the process described above, is therefore also provided by this invention.

The examples which follow illustrate the process according to the invention further. All parts or percentages given are, just as in the remaining description and in the claims, by weight, unless stated otherwise. As far as percentages are based on phosphite or phosphonite, they refer to phosphite or phosphonite in the melt unless a different reference amount is expressly stated. The structural formulae of the phosphites, phosphonites and amines used in the examples are, if not stated directly, listed above in the text.

EXAMPLE 1

300 g of phosphite Ph-1 are brought to 70°-75° C. together with 225 g of isopropanol, 2.25 g of toluene and 30 g of amine A (=triisopropanolamine) with stirring. The resulting homogeneous melt is added over a period of about 1 hour with stirring to a suspension of 20 g of Ph-1 in 450 g of isopropanol and 20 g of amine A whose temperature during this process is maintained at 20°-30° C. by cooling. The mixture is then cooled to 10°-15° C. and stirred in this temperature range for another 3 hours. The crystalline product is then filterat off and dried at 60° C. under reduced pressure.

Elemental analysis gives an amine A content of 1.2% by weight (relative to phosphite) for the dry product.

A sample serving as comparison is crystallized without adding an amine.

Equal mounts of the product are then subjected to the following tests of resistance to hydrolysis:

a) During storage, the time is measured in which upon visual inspection the initial powder starts to deliquesce (transition p-c) and the time which expires until the material is liquid (transition c-1). At the last-mentioned point in time, the weight increase during the duration of storage is noticed; the weight increase gives an indication of the water absorption of the material. The test conditions (temperature and atmospheric humidity during storage) are given in the particular examples.

b) After 8 hours of storage at 70° C. and 100% atmospheric humidity, the phosphite Ph-1 content is determined by liquid chromatography.

The results can be seen from Table 1.

EXAMPLE 2-13

Compound Ph-1 is stabilized with amines A, C, E, H, J, K, P, Q and U by the method described in Example 1; however, in contrast to Example 1, no phosphite and no amine are introduced into the crystallization medium at the beginning. The product obtained is tested for resistance to hydrolysis as described in Example 1. The test conditions in test a: storage at 50° C. and 75% atmospheric humidity. Further conditions and test results are summarized in Table 1.

In Table 1 and the following tables, the column headings have the following meaning:

    ______________________________________                                         % intr.: amount of amine in the melt, % given is based on                               phosphite or phosphonite in the melt;                                 % cont.: amine content in the phosphite or phosphonite after                            crystallization;                                                      Solv1, %:                                                                               main solvent for the melt, % given is based on                                 phosphite or phosphonite in the melt;                                 Solv2, %:                                                                               further solvent for the melt, % given is based on                              phosphite or phosphonite in the melt;                                 T/°C.:                                                                           temperature range of the melt or crystallization                               medium;                                                               Solvent, %:                                                                             solvent for crystallization medium, % given is                                 based on phosphite or phosphonite in the melt;                        IPA:     isopropanol;                                                          TOL:     toluene;                                                              MeOH:    methanol;                                                             % seed cr.:                                                                             initial charge of phosphite as seed crystals, %                                given is based on phosphite or phosphonite in the                              melt;                                                                 % amine: initial charge of amine in the crystallization                                 medium, % given is based on phosphite or                                       phosphonite in the melt;                                              % dec. (8 h):                                                                           decomposition of the sample after 8 h in %                                     (100% = phosphite content at the beginning of the                              test) [test b)];                                                      p-c/h:   time in hours until deliquescence begins [test a)];                   c-l/h (% W):                                                                            time in hours until sample has become liquid (clear                            solution). Numbers given in brackets: weight                                   increase of the sample compared with the                                       beginning of the test (% by weight is based on the                             beginning of storage = water content) [test a)].                      ______________________________________                                    

                                      TABLE 1                                      __________________________________________________________________________     Stabilization of bis(2,4,-di-tert-butyl-6-methylphenyl) ethyl phosphite        (Ph-1)                                                                         MELT                          CRYST. MEDIUM      TEST RESULTS                  Ex.      %  %                 Solvent,                                                                            %    %        % dec.   c-l/h                No.  Amine                                                                              intr.                                                                             cont.                                                                             Solv1, %                                                                            Solv2, %                                                                             T/°C.                                                                       %    seed cr.                                                                            amine                                                                              T/°C.                                                                        (8 h)                                                                               p-c/h                                                                              (%                   __________________________________________________________________________                                                               W)                   Compari-                                                                            none                                                                               0  0  IPA, 75                                                                             TOL, 0.75                                                                            70-75                                                                              IPA, 150                                                                            0    0   20-30                                                                               85 (n.2                                                                             005  37 (2.5)            son                                                                             1   A   10 1.2                                                                               IPA, 75                                                                             TOL, 0.75                                                                            70-75                                                                              IPA, 150                                                                            6.7  6.7 20-30                                                                               5    056 126 (2.2)             2   A   20 2.7                                                                               IPA, 75                                                                             TOL, 0.75                                                                            70-75                                                                              IPA, 150                                                                            0    0   20-30                                                                               3.2  110 171 (2.0)             3   Q   20 3.5                                                                               IPA, 75                                                                             TOL, 0.75                                                                            70-75                                                                              IPA, 150                                                                            0    0   20-30                                                                               5    025 >120                  4   P   5  1.0                                                                               IPA, 75                                                                             TOL, 0.75                                                                            70-75                                                                              IPA. 150                                                                            0    0   20-30                                                                               13.4 056 144 (1.5)              5  P   10 2.7                                                                               IPA. 75                                                                             TOL, 0.75                                                                            70-75                                                                              IPA, 150                                                                            0    0   20-30                                                                               3.1  160 220  .sup.            6   P   20 3.8                                                                               IPA, 75                                                                             TOL, 0.75                                                                            70-75                                                                              IPA, 150                                                                            0    0   20-30                                                                               1.0  200 312 (1.1)             7   C   20 2.9                                                                               IPA, 75                                                                             TOL, 0.75                                                                            70-75                                                                              IPA, 150                                                                            0    0   20-30                                                                               15.2 040  72 (2.7)             8   J   10 1.5                                                                               IPA, 75                                                                             TOL, 0.75                                                                            70-75                                                                              IPA, 150                                                                            0    0   20-30                                                                               9.5  040  72 (1.0)             9   J   20 3.1                                                                               IPA, 75                                                                             TOL, 0.75                                                                            70-75                                                                              IPA, 150                                                                            0    0   20-30                                                                               2.0  135 171 (1.3)            10   H   10 6.5                                                                               IPA, 75                                                                             TOL, 0.75                                                                            70-75                                                                              IPA, 150                                                                            0    0   20-30                                                                               12.4 056 120 (1.5)            11   K   10 1.4                                                                               IPA, 75                                                                             TOL, 0.75                                                                            70-75                                                                              IPA, 150                                                                            0    0   20-30                                                                               19.4 032  48 (1.0)            12   U   10 0.9                                                                               IPA, 75                                                                             TOL, 0.75                                                                            70-75                                                                              IPA, 150                                                                            0    0   20-30                                                                               4.5  056 120 (1.6)            13   E   10 0.9                                                                               IPA, 75                                                                             TOL, 0.75                                                                            70-75                                                                              IPA, 150                                                                            0    0   20-30                                                                               8.6  032  48                  __________________________________________________________________________                                                               (0.8)           

EXAMPLES 14-17

A commercial phosphonite mixture containing Ph-3 as the main component is stabilized by the method described in Examples 2-13; composition of the batch: ##STR55##

The stabilized mixture is tested for resistance to hydrolysis by means of test a); test conditions: storage at 50° C. and 75% atmospheric humidity. Process conditions and test results are summarized in Table 2.

EXAMPLES 18-23

Compounds Ph-5 and Ph-6 are stabilized by the method described in Examples 2-13 and tested for resistance to hydrolysis by means of test a). Test conditions: storage at 50° C. and 75% atmospheric humidity. Test conditions and test results are summarized in Tables 3 and 4.

EXAMPLES 24-29

Compound Ph-2 is stabilized by the method described in Examples 2-13 and tested for resistance to hydrolysis by means of test a); test conditions: storage at 70° C. and 100% atmospheric humidity. Process conditions and test results are summarized in Table 5.

EXAMPLES 30-33

A commercial phosphonite mixture containing Ph-3 as the main component is stabilized by the method described in Examples 2-13; composition of the batch (for formulae, see Examples 14-17):

    ______________________________________                                         Ph-3:             35%                                                          Ph-2:             09%                                                          Ph-3b:            20%                                                          Ph-3c:            04%                                                          Ph-3d:            15%                                                          further compounds:                                                                                17%.                                                        ______________________________________                                    

The stabilized mixture is tested for resistance to hydrolysis by means of test a); test conditions: storage at 50° C. and 75% atmospheric humidity.

Process conditions and test results are summarized in Table 6.

                                      TABLE 2                                      __________________________________________________________________________     Stabilizing of a phosphonite mixture containing the main component of the      formula                                                                         ##STR56##                                                                     MELT                           CRYST. MEDIUM                                   Ex.                    Solv 2,                                                                                       %             TEST RESULTS               No. Amine                                                                              % intr.                                                                            % cont.                                                                             Solv 1, %                                                                            %   T/°C.                                                                       Solvent, %                                                                            seed cr.                                                                            % amine                                                                             T/°C.                                                                       p-c/h                                                                              c-l/h (%               __________________________________________________________________________                                                             W)                     Comp-                                                                          arison                                                                             none                                                                                0  0    IPA, 300                                                                             --  60-65                                                                              MeOH, 400                                                                             0    0    15-20                                                                               110                                                                               150 (15)               14  J   20  3.4  IPA, 300                                                                             --  60-65                                                                              MeOH, 400                                                                             0    0    15-20                                                                              >360                       15  N    5   5   IPA, 300                                                                             --  60-65                                                                              MeOH, 400                                                                             0    0    15-20                                                                               260                       16  N   10  10   IPA, 300                                                                             --  60-65                                                                              MeOH, 400                                                                             0    0    15-20                                                                              >360                       17  C   20  2.8  IPA, 300                                                                             --  60-65                                                                              MeOH, 400                                                                             0    0    15-20                                                                              >360                       __________________________________________________________________________

                                      TABLE 3                                      __________________________________________________________________________     Stabilization of the compound of the formula                                    ##STR57##                                                                     MELT                           CRYST. MEDIUM                                   Ex.                    Solv 2,        %             TEST RESULTS               No. Amine                                                                              % intr.                                                                            % cont.                                                                             Solv 1, %                                                                            %   T/°C.                                                                       Solvent, %                                                                            seed cr.                                                                            % amine                                                                             T/°C.                                                                       p-c/h                                                                              c-l/h (%               __________________________________________________________________________                                                             W)                     Comp.                                                                              none                                                                                0  0    TOL, 250                                                                             --  75-80                                                                              MeOH, 500                                                                             0    0    20-25                                                                              5   17 (30)                18  A   20  0.5  TOL, 250                                                                             --  75-80                                                                              MeOH, 500                                                                             0    0    20-25                                                                              8   24 (33)                19  P   20  2.0  TOL, 250                                                                             --  75-80                                                                              MeOH, 500                                                                             0    0    20-25                                                                              8   24 (24)                20  N   10  4.8  TOL, 250                                                                             --  75-80                                                                              MeOH, 500                                                                             0    0    20-25                                                                              15  48 (37)                21  N   20  10.5 TOL, 250                                                                             --  75-80                                                                              MeOH, 500                                                                             0    0    20-25                                                                              15  48                     __________________________________________________________________________                                                             (28)              

                                      TABLE 4                                      __________________________________________________________________________     Stabilization of the compound of the formula                                    ##STR58##                                                                     MELT                            CRYST. MEDIUM                                  Ex.                    Solv 2,         %    %       TEST RESULTS               No. Amine                                                                              % intr.                                                                            % cont.                                                                             Solv 1, %                                                                            %    T/°C.                                                                       Solvent, %                                                                            seed cr.                                                                            amine                                                                              T/°C.                                                                       p-c/h                                                                              c-l/h (%               __________________________________________________________________________                                                             W)                     Comp.                                                                              none                                                                                0  0    TOL, 500                                                                             IPA, 500                                                                            75-80                                                                              IPA, 500                                                                              0    0   15-20                                                                                96                                                                                168 (30)              22  A   20  1.1  TOL, 500                                                                             IPA, 500                                                                            75-80                                                                              IPA, 500                                                                              0    0   15-20                                                                              >400                       23  N   20  2.0  TOL, 500                                                                             IPA, 500                                                                            75-80                                                                              IPA, 500                                                                              0    0   15-20                                                                               210                                                                               240                    __________________________________________________________________________

                                      TABLE 5                                      __________________________________________________________________________     Stabilization of tris(2,4,-di-tert-butylphenyl) phosphite (Ph-2)                      MELT                    CRYST. MEDIUM                                              %  %       Solv2,   Solvent,                                                                            %    %       TEST RESULTS                  Ex. No.                                                                               Amine                                                                              intr.                                                                             cont.                                                                             Solv1, %                                                                            %   T/°C.                                                                        %    seed cr.                                                                            amine                                                                              T/°C.                                                                       p-c/h  c-l/h (%               __________________________________________________________________________                                                             W)                     Comparison                                                                            none                                                                               0  0  TOL, 200                                                                            --  75   IPA, 600                                                                            0    0   20-30                                                                              026     47 (27)               24     N   2  0.7                                                                               TOL, 200                                                                            --  75   IPA, 600                                                                            0    0   20-30                                                                              216    240 (11)               25     N   5  1.8                                                                               TOL, 200                                                                            --  75   IPA, 600                                                                            0    0   20-30                                                                              216    240 (11)               26     N   10 5.1                                                                               TOL, 200                                                                            --  75   IPA, 600                                                                            0    0   20-30                                                                              240    312 (16)               27     N   25 16.1                                                                              TOL, 200                                                                            --  75   IPA, 600                                                                            0    0   20-30                                                                              >312   >312 (0)               28     P   2  0.1                                                                               TOL, 200                                                                            --  75   IPA, 600                                                                            0    0   20-30                                                                              192    216                    29     P   5  3.8                                                                               TOL, 200                                                                            --  75   IPA, 600                                                                            0    0   20-30                                                                              216    240                    __________________________________________________________________________

                                      TABLE 6                                      __________________________________________________________________________     Stabilization of a phosphonite mixture containing the main component of        the formula                                                                     ##STR59##                                                                            MELT                   CRYST. MEDIUM         TEST RESULTS               Ex. No.                                                                               Amine                                                                              % intr.                                                                            % cont.                                                                             Solvent, %                                                                           T/°C.                                                                       Solvent, %                                                                            % seed cr.                                                                           % amine                                                                             T/°C.                                                                       p-c/h                                                                              c-l/h (%               __________________________________________________________________________                                                             W)                     Comparison                                                                            none                                                                               0   0    IPA, 400                                                                             75  MeOH, 400                                                                             0     0    20-30                                                                               24  48 (3.4)              30     N   5   7.5  IPA, 400                                                                             75  MeOH, 400                                                                             0     0    20-30                                                                              348 360 (0.2)              31     N   10  18.2 IPA, 400                                                                             75  MeOH, 400                                                                             0     0    20-30                                                                              504 816 (2.2)              32     N   25  32.3 IPA, 400                                                                             75  MeOH, 400                                                                             0     0    20-30                                                                              648 840 (0.9)              33     P   2   2.1  IPA, 400                                                                             75  MeOH, 400                                                                             0     0    20-30                                                                              240 312                    __________________________________________________________________________                                                             (2.6)             

EXAMPLE 34-35

Compound Ph-5 is stabilized by the method described in Examples 2-13. The crystallization medium used is isopropanol without any further addition. The unstabilized and stabilized compound are tested for resistance to hydrolysis by means of test a). Test conditions: storage at 50° C. and 75% atmospheric humidity.

Further process conditions and test result (c-l/h =time in hours until sample becomes deliquescent) are summarized in Table 7.

                                      TABLE 7                                      __________________________________________________________________________     Stabilization of the compound of the formula                                    ##STR60##                                                                     MELT                   CRYST. MEDIUM RESULTS                                   Ex. No.                                                                             Amine                                                                              % intr.                                                                            % cont.                                                                             Solv., %                                                                            T/°C.                                                                        Solv., % T/°C. c-l/h                        __________________________________________________________________________     Comp.                                                                               none                                                                               0   0    TOL, 250                                                                            75   IPA, 600 20-30 8                                   34   N   5   1.3  TOL, 250                                                                            75   IPA, 600 20-30 24                                  35   P   5   0.15 TOL, 200                                                                            75   IPA, 600 20-30 24                                  __________________________________________________________________________

The examples show that the phosphites prepared and stabilized according to the invention exhibit much better resistance to hydrolysis in moist air than unstabilized phosphites. 

What is claimed is:
 1. A crystalline organic phosphite or phosphonite, stabilized against hydrolysis, prepared by introducing a mixture, comprising a phosphite or phosphonite, a solvent or a solvent mixture, and 0.1 to 100% by weight (relative to phosphite or phosphonite) of an amine and having a temperature of 50°-100° C., as a homogeneous melt into a liquid crystallization medium whose temperature during the addition is maintained 10°-70° C. below the temperature of the melh wherein the phosphite is of the formula P(OR¹)₃ wherein each radical R¹ is independently of the other hydrogen or a hydrocarbon radical which optionally contains a hetero atom selected from the group consisting of N, O, F, Si, P, S, Cl, Br, Sn or I with the proviso that a maximum of two of the three radicals R¹ are hydrogen and wherein the phosphonite is of the formula P(OR²)₂ R³ wherein each radical R² and R³ is each independently of the other as defined for R¹ or halogen and wherein the amine is of the formula I ##STR61## in which X¹ and X², independently of one another, are H, C₁ -C₂₀ alkyl, C₄ -C₂₀ alkyl which is interrupted by one or more --O-- and unsubstituted or substituted by one or more hydroxyl groups, or is C₂ -C₂₀ hydroxyalkyl, and X³ is C₂ -C₂₀ alkyl, C₄ -C₂₀ alkyl which is interrupted by one or more --O-- and unsubstituted or substituted by one or more hydroxyl groups, or is --(CH₂)_(m) --NX¹ X², or C₂ -C₂₀ hydroxyalkyl, in which X² and X³ together are --(CH₂)_(m) --, --C₂ H₄ --O--C₂ H₄ -- or --C₂ H₄ --NX¹ --C₂ H₄ --, m being an integer from the range 4 to 6 and X¹ and X² being as defined above; or a cyclic sterically hindered amine containing at least one group of the formulae II or III ##STR62## in which G is hydrogen or methyl, and G₁ and G₂ are hydrogen, methyl or together are ═O.
 2. A phosphite or phosphonite according to claim 1 wherein the melt comprises an alcohol or a hydrocarbon in an amount of 20 to 500% by weight, relative to the phosphite or phosphonite, as the main solvent or a further solvent in an amount of 0-50% by weight, relative to the main solvent.
 3. A phosphite or phosphorlite according to claim 1 wherein the temperature of the melt is 55°-90° C.
 4. A phosphite or phosphorlite according to claim 1 wherein tile difference in temperature between melt and crystallization medium is 30°-70° C.
 5. A phosphite or phosphonite according to claim 1, wherein the crystallization medium is maintained at a temperature which is at least 10° C. below the resulting temperature of the liquid.
 6. A phosphite or phosphonite according to claim 1 wherein 80-800% by weight (relative to the phosphite or phosphonite) of a solvent is used as the crystallization medium.
 7. A phosphite or phosphonite according to claim 6 wherein a C₁ -C₅ alkanol or a mixture of various C₁ -C₅ alkanols is used as the crystallization medium.
 8. A phosphite or phosphonite according to claim 6 wherein the crystallization medium consists of a suspension of 2 to 20% by weight of crystalline phosphite or phosphonite, relative to the phosphite or phosphonite in the melt.
 9. A phosphite or phosphonite according to claim 1 wherein the crystallization medium is saturated with 50-100% by weight of amine.
 10. A phosphite or phosphonite according to claim 1 wherein the melt contains 0.1 to 50% by weight of amine (relative to the phosphite or phosphonite).
 11. A phosphite or phosphonite according to claim 1 wherein the amine is a tertiary amine of the formula I or a cyclic sterically hindered amine containing at least one group of the formulae II or III, in which G is hydrogen and G₁ and G₂ are hydrogen or together are a substituent ═O. 